Pay one's debt and set free (9)
I believe the answer is:
discharge
This could be a double definition.
'pay one's debt' is the first definition.
'discharge' can be an answer for 'pay' (I've seen this before). I am not sure about the 'one's debt' bit.
'set free' is the second definition.
(thesaurus)
'and' acts as a link.
Can you help me to learn more?
(Other definitions for discharge that I've seen before include "let go" , "cashier" , "Send away - perform" , "unload" , "Sack or fire weapon" .)